Process for operation of a weaving machine as well as application of the process

ABSTRACT

A weaving machine having a filling breakage detector for generating an error signal upon breakage of a filling thread. This error signal then stops the weaving machine. A pick finding process is then initiated in which the weaving program is set back and then blocked. After removal of any filling thread in the open shed, the weaving machine is operated until the preceding shed is opened enabling the removal of the filling thread. If this is the ruptured filling thread, it is replaced by a new filling thread, the weaving program is unblocked and the weaving machine is operated in its normal sequence. If the filling thread is not ruptured once or if another ruptured filling thread is detected in a preceding shed, the pick finding process is repeated. The cloth takeoff and the warp letoff are also set back correspondingly with the weaving program.

BACKGROUND OF THE INVENTION

1. Field of the Invention:

The invention is directed to a process and apparatus for controlling aweaving machine which is stopped by an error signal of a fillingbreakage detector, wherein for pick finding, the weaving program of acontrol device of a shedding apparatus is set back and the pick findingoccurs with the weaving machine running forward, and at least the clothtakeup being correspondingly set back.

2. Description of Related Art:

Processes of the above-named type are known, for instance, from theDE-OS No. 25 14 248. The process described there has, however, thedisadvantage that the weaving machine apart from the stop, which iscaused by an error signal of a filling stop motion, must perform twoadditional stops during a pick finding cycle, before the normal weavingprocess can be resumed. For the pick finding, furthermore, only onenormal shed is available, so that tight limits are set to the stoppingand the restarting of the weaving machine. Thus, the known process iscumbersome and time-consuming.

SUMMARY OF THE INVENTION

It is an object of the invention to create a process for control of aweaving machine which does not exhibit the above-mentioneddisadvantages. Furthermore, also a double dobby weaving machine must isoperable according to this process.

The above object is achieved in a process for controlling a weavingmachine wherein, in each pick finding cycle, after being set back, thestep-by-step action of the weaving program in each pick finding cycle isblocked at least for that shed, which follows the shed in which theruptured filling thread is being searched for, in such a way that theshed to be examined remains open, at least as a double shed, during atleast two filling cycles, whereupon the continuation of the sequentiallycorrect next normal weaving process is triggered or, prior thereto, thepick finding cycle is repeated for respective preceding shedsaccompanied by corresponding set backs of the weaving program, until theruptured filling thread is found.

By designing the shed which has to be examined for the filling cycle asa double shed there results the advantage that considerable latitude isgiven with respect to stopping the weaving machine. On the other hand itis possible to immediately restart from this position of the weavingmachine wich serves for the purpose of pick finging, without that theweaving machine would have to be first of all brought into a startingposition. Thus the process is rendered to be more simple, more rapid andthus more economical.

It is particularly advantageous if the weaving machine stops in thefirst shed crossing following an error signal of the filling breakagedetector. This makes possible, in particular in the case of double dobbyweaving machines, the synchronization of the two weaving machine units.For a single weaving machine this stoppage may occur between the firstand second shed crossing following the filling thread rupture, becausethere are no such high requirements with respect to accuracy in case ofstoppage.

Particularly advantageous is also a refinement of the process in whichat least a fabric takeoff and possibly the warp letoff is set back by amagnitude G, whereby G=K·L, in which: L is the cloth length between twofilling insertions and k Correction factor, wherein K=0.1 to 4, sincethen, possible errors of the cloth layer can be avoided. The correctionfactor can be freely chosen and depends, as a rule, on the properties ofthe cloth to be fabricated. The correction factor is therefore adjustedonly once for the production of a specific cloth.

After the first stoppage of the weaving machine caused by the fillingstop motion, the process can appropriately be triggered manually. It is,however, also imaginable to trigger the pick finding cycle directly bythe error signal of the filling breakage detector.

The process can utilized for weaving machines of any type. Particularlyadvantageous is the use in a double dobby weaving machine. Accordingly,the weaving machine unit which is not experiencing the filling threadrupture can be decoupled during pick finding. It is, however, alsopossible to decouple the weaving machine unit not experiencing thefilling thread rupture. The shedding apparatus of the weaving machineunits can run synchronously or be displaced phasewise by 180°.

Embodiment examples of the invention are described in the following withparticularity with the help of drawings, wherein it is shown in:

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1 a simple weaving machine in cutout and in elevation of the warpletoff apparatus;

FIG. 2 the weaving machine of FIG. 1 in section II-II of the FIG. 1;

FIG. 3 the reversing gear unit in side view;

FIG. 4 the reversing gear unit in section IV-IV of the FIG. 3;

FIG. 5 a double dobby weaving machine in picture presentation;

FIGS. 6a to 6d a shed diagram (FIGS. 6a to 6c) and a cloth diagram (FIG.6d) in various phases of the pick finding in a simple weaving machine;

FIGS. 7a to 7d of shed diagram (FIGS. 7a to 7c) and a cloth diagram(FIG. 6d) in various phases of the pick finding in a double dobbyweaving machine with simultaneous running of both weaving machine units;and

FIGS. 8a to 8d a shed diagram (FIGS. 8a to 8c) and a cloth diagram (FIG.8d) in various phases of the pick finding in a double dobby weavingmachine, whereby the weaving machine unit not experiencing a fillingthread rupture is decoupled.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 to 4 show a first embodiment of a weaving machine comprising awarp letoff apparatus 2, a fabric takeoff apparatus 4, a sheddingapparatus 6, a principal drive 8 with a drive motor not shown in detailhere, a reversing gear unit 10 connected with the warp letoff apparatus2 and the fabric takeoff apparatus 4, as well as an electonic controldevice 12 for a weaving program. Connected at the principal drive 8 in amanner, for example, known from the U.S. Pat. No. 4,305,434 which is notshown here in detail, are a weaving reed 14 and a filling threadinserting element 16.

The warp letoff apparatus 2 contains a warp beam 18, whose shaft isdriven by a worm gear 22. From the warp beam 18, the warp threads 24pass over a back rest 26 to the shafts 28 of the shedding apparatus 6,which serve for creating and changing the warp shed 30. A filling threadinserting unit 16 periodically engages into the warp shed 30. Theinserted filling thread is attached at the cloth edge 32 by means of theweaving reed 14. The weaved cloth 34 is tightened by the feed roller 36and is pulled off and wound up on the cloth beam 38. The fabric takeoffapparatus 4 containing the feed roller 36 and the cloth beam 38 isdriven by means of a regulator gear 40.

For driving the warp letoff apparatus 2, the fabric takeoff apparatus 4and the shedding apparatus 6, an auxiliary drive shaft 46 is connectedat the main drive 8 by means of bevel gears 42, 44. This auxiliary driveshaft 46 has a gear wheel 48, which drives, by means of a tooth belt 50,a drive wheel 52 for the warp letoff apparatus 2 and the fabric takeoffapparatus 4, as well as a drive wheel 54 for the shedding apparatus 6.The shedding apparatus 6 contains a dobby 56, whose drive shaft 58 isconnected with the drive wheel 54, possibly with interposition of aclutch 60. The dobby 56 which, for instance, is constructed andcontrolled according to the U.S. Pat. Nos. 4,493,346 and 4,452,281,comprises shaft swing arms 62, which are respectively connected with theshaft 28 by means of a lever drive 64 and which enable to hold the shedopen over at least two filling thread insertion processes.

The drive wheel 52, for driving the warp letoff apparatus 2 at thefabric takeoff apparatus 4, is connected with a drive shaft 66 by meansof the reversing gear unit 10, designed as a superimposed gear, whichshaft drives on the one hand the worm gear 22 of the warp gear, whichdrive shaft 66 drives, at one end, the worm gear 22 of the warp letoffapparatus 2 and, at the other end, the regulator gear 40 of the fabrictakeoff apparatus 4. The drive wheel 52 is arranged in a bearing sleeve68, which is supported on the drive shaft 66 so as to be freelyrotatable with respect to the drive shaft 66. The bearing sleeve 68protrudes into a housing 70 and carries a gear wheel 72 with which aplanetary wheel 74 meshes. This planetary wheel 74 is arranged upon ashaft 76 so as to be non-rotatable with respect to shaft 76. The shaft76 is supported in a satellite carrier 78 so as to be rotatable withrespect to same, which carrier 78 upon its part is rotatably supportedon the drive shaft 66. On the shaft 76, on the other side of thesatellite carrier 78, another planetary wheel 80 is connected to benon-rotatable with respect to the shaft 76. The second planetary wheel80 meshes with a gear wheel 82 arranged on the drive shaft 66 to benon-rotatable with respect to the drive shaft 66. The satellite carrier78 is designed as a worm wheel and comprises, at its periphery, a set ofworm gear teeth 84 which coacts with a worm wheel 86, a drive shaft 88thereof being connected to an auxiliary motor 90. The worm drive formedout of the set of worm gear teeth 84 and the worm wheel 86 is preferablydesigned to be self-locking. The reverse gear unit 10 is furthermoreprovided with a braking device 92 to prevent coasting. The brakingdevice 92 comprises a friction disk 94 arranged on the drive shaft 88 tobe non rotatable with respect to the shaft 88, with which coactsfriction disk 96 which is arranged in the housing 70 to be non-rotatablewith respect to the housing 70. A lug 98 arranged on the friction disk96 engages a groove 100 in the housing 70, which lies parallel to thedrive shaft 88 and prevents twisting of the friction disk 96. Apreloading spring 102 preloads the friction disk 96 against the frictiondisk 94 connected to the drive shaft 88.

Drive shaft 66 is interrupted by means of a clutch 104 at the portionrunning towards the warp letoff apparatus 2. This clutch 104 is, forexample, designed as a claw clutch, which can be switched over by aswitching lever 106 and an actuation device 108, so that the drive ofthe warp letoff apparatus 2 can be switched off if required.

The weaving machine is equipped with the electronic control device 12,which, on the one hand, is connected with the dobby 56 of the sheddingapparatus 6 and, on the other hand, with the auxiliary motor 90 of thereversing gear unit 10. At the control device 12 there are connectedalso warp breakage detectors, as the filling breakage detector 110.Furthermore, the control device 12 has a set of pushbuttons fortriggering of various functions:

ST: Normal start

SP: Normal stop

SZ: Preparation of the pick finding cycle

KG: Normal creep speed forward

K: Correction factor triggering

The correction factor is recorded by means of a coding switch previouslyand applicable to a specific class and is triggered by means of thepushbutton K. The correction factor K can be freely triggered as forinstance after: normal or longer stoppage of the weaving machine; warpthread ruptures; pick finding.

The electronic control device 12 which is suitably equipped with aprocessor, enables switching the weaving program backwards with theweaving machine running forward, so that the dobby 56, which is indeeddriven in the forward direction, performs a reverse motion sequence.Simultaneously, the control device 12 controls the auxiliary motor 90 ofthe reversing gear unit 10, so that, for the purpose of pick findingafter a filling thread ruptures, the warp letoff apparatus 2 and thefabric takeoff apparatus 4 can be switched into reverse, as isexplained, with the help of FIGS. 6a to 6d in some detail in thedescription following further below.

FIG. 5 shows a double dobby weaving machine in perspective, in which twoweaving machine units 112, 114, arranged one next to the other areconnected to a common drive device 116. Each weaving machine unit 112,114 contains its own shedding apparatus 118, 120 which are alsoconnected to the common driving device 116. Furthermore, the doubledobby weaving machine contains a control device 122 with applicablepushbuttons ST, SP, SZ, KG and K, whose function has been explained inconnection with FIG. 1.

The double dobby weaving machine, which as a matter of fact is explainedin detail in the U.S. Pat. No. 4,448,220, is equipped as a two-phasegripper weaving machine. The shedding apparatus 118, 120 actuates therespective shaft 124, 126 of the individual shedding apparatus 118, 120of the weaving machine units 112, 114 in a phasewise staggered mannerand through an angle of 180°. The control of the double dobby weavingmachine is described with particularity in the FIGS. 7a to 7d as well as8a to 8d.

The FIGS. 6a, 6b and 6c show shed diagrams for a weaving machine of theFIGS. 1 to 4 in a first pick finding cycle as well as in second andthird pick finding cycles. FIG. 6d show the cloth diagram pertaining tothe above shed diagrams. The individual sheds 128 formed by the warpthreads 24 carry, respectively, the applicable weaving program stagenumbers 3 to 7. In the individual sheds 128, the filling threads 130 areinserted. At the timing spot 132, the cycle pulse for the next shed butone is taken off.

The pick finding occurs as follows:

As can be gathered from FIG. 6a, the filling breakage detector 110 inthe shed 128 detects at the weaving program stage number 5, a rupturedfilling thread 130a. Thereupon, a stop impulse is triggered and theweaving machine is stopped at the end of the following shed 128 havingthe weaving program stage number 5+1=6. Simultaneously, the weavingprogram of the control device 12 is switched back by one weaving programstage and a counter therein is blocked, which responds to the timingspot 132. A filling thread 130b, possibly located within this shed, canbe removed. Now the pushbutton KG is actuated and the weaving machinecontinues to run at creeping speed until the next preceding shed 128having the setback weaving program stage number 5 is opened. Since thecounter for the timing spot 132 is blocked, the weaving program cannotbe switched further, so that the weaving program stage number 5 appliesfor the shed to be closed. This means that the shed does not yet closeat the first pick finding process but rather only after the second pickfinding process. The weaving machine stops now in the first half of thethus formed double shed 134 with the weaving program stage number 5. Apossibly ruptured filling thread 130a can now be removed. If the fillingthread rupture is eliminated by this, then the weaving machine can, bymeans of pressing the pushbutton ST, be put back into operation in orderto continue the normal weaving process and the normal sequentiallycorrect weaving program stage numbers 6, 7, etc. follow. The firstfilling thread 130 is already inserted into the second half of thedouble shed 134. During this first pick finding cycle, the fabrictakeoff and the warp letoff are put back by one filling stage, as can begathered from the cloth diagram in FIG. 6d.

If one detects at the double shed 134 having the weaving program stagenumber 5, that an additional further ruptured filling thread must besearched for, then the pushbutton SZ must be actuated which prepares thefurther pick finding cycle, in that the weaving program at the controldevice is again put back by one weaving program stage and the timingcounter is blocked. By a further operation of the pushbutton KG, theweaving machine is switched into creeping speed and operates until apreceding shed having the weaving program stage number 4 is opened.Simultaneously the fabric takeoff and warp letoff are put back by onefilling cycle. If one now ascertains that the pick finding is nowfinished, then the normal weaving progress can again be triggered byoperating the starting button ST, whereby already again a filling thread130 is inserted into the second half of the double shed 134 with theweaving program stage number 4.

The weaving process progresses now again normally. If, however, onedetects in the first half of the double shed 134 that another rupturedfilling thread is to be searched for, then an additional pick findingcycle of the nature described above occurs.

The FIGS. 7a to 7d show a first, second and third pick finding cycle fora double dobby weaving machine of the type shown in FIG. 5, wherein theupper shed diagram pertains to the righthand weaving machine unit 112and the lower shed diagram pertains to the lefthand weaving machine unit114. If the filling breakage detector of the righthand weaving machineunit 112 detects a filling thread rupture in the shed 128 with theweaving program stage number 5, then the double dobby weaving machinestops at the following thereupon shed crossing point 136. By operatingthe pushbutton SZ, the first pick finding cycle is triggered. Thisentails that the weaving program in the control device is set back byone weaving program stage and that the timing counter is temporarilyblocked. The regulator for the fabric takeoff and the weaving machineunit in which the filling thread rupture has been detected is set back.The entire double dobby weaving machine is futhermore switched forwardin creeping speed, and indeed by two filling stages or one revolution ofthe shaft of the shedding apparatus. By means of the setting back of theweaving program stage and the blocking of the timing counter again adouble shed 134 with the weaving program stage number 5 is generated.The double dobby weaving machine now stops in the false crossing point138 of the double shed 134. Ruptured filling thread 130a are removed. Ifone ascertains that no additional ruptured filling thread exists, thenthe double dobby weaving machine can again be switched on by actuationof the starting button ST and can be put into the normal weavingprocess, whereby a first filling thread 130 is already inserted into thesecond half of the double shed 134.

If however an additional ruptured filling thread is detected, then againthe pushbutton SZ is actuated whereupon a second pick finding cycleaccording to FIG. 7b is triggered. The double dobby weaving machine nowstops again in a double shed 134 with the next lower weaving programstage number 4. A ruptured thread 130a is removed. Should no additionalruptured filling threads be detectable, then the double dobby weavingmachine can be again restarted by actuation of a pushbutton ST and thenormal weaving process can again be triggered. Into the second half ofthe double shed 134 already a first filling thread 130 is beinginserted.

With this design of the control device and a double dobby weavingmachine, there results the advantage that the double dobby weavingmachine is constructed in a very simple manner since no pick findinggear is required. This results in a good accessibility of the sheddingapparatus. Only a pushbutton actuation is required for triggering of thepick finding cycle.

For the cloth reversing motion, the regulator is equipped with aregulator clutch in order to couple the regulator into reverse. In theFIGS. 8a to 8c, the shed diagrams of a double dobby weaving machine areshown, in which, during removal of a filling thread rupture in oneweaving machine unit, the other weaving machine unit is decoupled untilthe pick finding is terminated. Hereby the pick finding occurs similarlyto the embodiment example of the FIGS. 7a to 7c. Inasmuch as in thedouble dobby weaving machine, in case of occurrence of a filling threadrupture and an indication by the filling stop motion breakage detector,the weaving machine unit concerned is brought to a stop in the next shedcrossing point 136, the accurate decoupling of the other weaving machineunit is assured. Since also during pick finding the weaving machine unitcomes to a stop in the false crossing point 138 of the double shed 134,exactly the same conditions result as during decoupling of the otherweaving machine unit, so that the reengagement can again occur in asynchronous manner, as this can be gathered from the shed diagrams ofthe FIGS. 8a to 8c as well as from the cloth diagram 8d. The advantageof this solution variant consists in that the double dobby weavingmachine is at a standstill and the shed is being moved only at therupture side. Thus there is no danger of damage at the sheddingapparatus. For a pick finding cycle also only one pushbutton actuationis required.

List of Reference Numbers

ST: Normal start

SP: Normal stop

SZ: Preparation for the pick finding cycle

KG: Normal creep speed forward

K: Correction factor-triggering

2: Warp letoff apparatus

4: Fabric takeoff apparatus

6: Shedding apparatus

8: Main drive

10: Reversing gear unit

12: Electronic control device

14: Weaving reed

16: Filling insertion unit

18: Warp beam

20: Shaft of 18

22: Worm gear

24: Warp threads

26: Back rest

28: Shaft

30: Warp shed

32: Cloth edge

34: Cloth

36: Feed roller

38: Cloth beam

40: Regulator gear

42: Bevel gear

44: Bevel gear

46: Auxiliary drive shaft

48: Gear wheel

50: Cog belt

52: Drive wheel for 2

54: Drive wheel for 6

56: Dobby

58: Drive shaft

60: Clutch

62: Shaft swing arm

64: Lever drive

66: Drive shaft

68: Bearing sleeve

70: Housing

72: Gear wheel

74: Planetary wheel

76: Shaft

78: Satellite carrier

80: Planetary wheel

82: Gear wheel

84: Worm gear tooth system

86: Worm gear

88: Drive shaft

90: Auxiliary motor

92: Braking device

94: Friction disk

96: Friction disk

98: Lug

100: Nut

102: Preloading spring

104: Clutch

106: Clutch lever

108: Actuation device

110: Filling breakage detector

112: Weaving machine unit, right side

114: Weaving machine unit, left side

116: Driving device

118: Shedding apparatus

120: Shedding apparatus

122: Control device

124: Shaft

126: Shaft

128: Shed

130: Filling thread

130a: Ruptured filling thread

130b: Additional filling thread

132: Timing place

134: Double shed

136: Shed crossing point

138: False crossing point

I claim:
 1. Process for controlling a weaving machine, which is stoppedby an error of a filling breakage detector, wherein for pick finding,the weaving program of a control device of a shedding apparatus is setback and the pick finding occurs with the weaving machine runningforward, and additionally at least the cloth takeup is correspondinglyset back, chracterized in that, after being set back, the step-by-stepaction of the weaving program in each pick finding cycle is blocked atleast for that shed, which follows the shed in which the rupturedfilling thread is being searched for, in such a way that the shed to beexamined reamains open, at least as a double shed, during at least twofilling cycles, whereupon the continuation of the sequentially correctnext normal weaving process is triggered or, prior thereto, the pickfinding cycle is repeated, for respective preceding sheds accompanied bycorresponding set backs of the weaving program, until the rupturedfilling thread is found.
 2. Process according to claim 1, characterizedin that during the first pick finding cycle, the weaving program for thenext shed, which finding cycle, the which the weaving machine stops, isset back to the weaving program stage number of the shed to be examinedpreferably by one weaving program stage number.
 3. Process according toclaim 2, characterized in that the weaving program, upon pick findingcycles following the first pick finding cycle, is respectively set backby respective additional weaving program stage numbers.
 4. Processaccording to claim 1, characterized in that the weaving machinestoppage, caused by the filling breakage detector; occurs in the firstshed crossing following the filling thread rupture.
 5. Process accordingto claim 1, characterized in that the weaving machine stoppage, causedby the filling breakage detector, occurs between the first and thesecond shed crossing following the filling thread rupture.
 6. Processaccording to claim 1, characterized in that, in each pick finding cycle,the weaving machine is stopped in the area of the double shed to beexamined.
 7. Process according to claim 1, characterized in that, ineach pick finding cycle, the weaving machine is stopped in the falsecrossing of the double shed.
 8. Process according to claim 1,characterized in that, for a pick finding cycle, the fabric takeoff andthe warp letoff are set back by a magnitude G, whereby

    G=K·L

in which: L is the cloth length between the two filling insertions, andK is a Correction factor, wherein K=0.1 to
 4. 9. Process according toclaim 1, characterized in that the pick finding cycle is triggered bymeans of a hand actuated switch.
 10. Process according to claim 1,characterized in that the pick finding cycle is triggered by means ofthe filling breakage detector.
 11. Application of the process accordingto claim 1 in a double dobby weaving machine, in which two weavingmachine units arranged one next to the other comprise a common drive andtwo separate shedding apparatus.
 12. Application according to claim 11,characterized in that the weaving machine unit not experiencing afilling thread rupture is allowed to continue to operate. 13.Application according to claim 11, characterized in that the weavingmachine unit not experiencing the filling thread rupture is decoupledfrom the drive during the pick finding in the other weaving machineunit.
 14. Application according to claim 11, characterized in that theshedding apparatus of the weaving machine units operate staggeredphasewise by 180°.